The problem is when this happens on the job. Then, you have a number of problems.
Was it genuinely consenting or did the more powerful person pressure the underling into a relationship? Did the underling really earn their promotion or did they get it because they are sleeping with the boss? Can the underling end the relationship and keep their job or would they have to first line up employment elsewhere?
Etc.
It's hard to distinguish from someone being attracted to not losing their job and feeling pressured into a relationship.
What you described in a vacuum is not wrong. Outside of a vacuum it makes the "pin the tail on the sociopath" game harder. Sociopaths and good meaning people are fighting a battle on the fields of eglatarianism right now.
Good people and sociopaths are on either side of the trench. There's good people fighting each other even though they're both trying to go through life taking the path of least evil. The sociopaths are saying crazy things they don't even mean because it attracts a fief. As a side effect, this emboldens each side because they're laser focused on the crazy coming from their opponents. The fight will go on longer than it needs to because the issues are muddied by the distracting crazy. This confuses people and makes them lose sight of empowering the good and stymieing the bad.
If history is a guide, a new "common sense" will arise that attempts to further protect the innocent and further stymie abusers. Somehow in order to make this bargain a bunch of evil people will get rich. Crazy how it always works.
Or we could just be moderating according to the guidelines, like we say. I'm confident the bulk of the community agrees with that. If they didn't, we'd never hear the end of it, where in fact the only accounts making these complaints are the few most ideologically strident ones.